[CMake] Possible bug in XCode backend and proposed workarounds

[Samuel Crow]

Hello,

I've built LLVM 2.9SVN successfully with CMake under XCode but had some 
workarounds needed to get to that point.

1.  Building in debug mode there was one archive file dependency that looked for 
the release folder instead of the debug folder.
2.  The install target failed to put a sudo -A in front of it.  This is required 
even when logged in as administrator on the Mac.
3.  Since there is no console input source available in XCode, a small 
executable was needed to accept the password and echo it to stdout for the sudo 
-A flag to use.  I've written such a requester box code in Qt and would be 
willing to share with the CMake team if desired.

Thanks for your time and efforts,

--Samuel D. Crow